Computing system designers face significant design challenges for embedded computing technologies, including, for example, reliability of operation, harsh operating environments, system interoperability, and data and system security. To meet these challenges, VMEbus International Trade Association (VITA), a standards-development body, has worked to define and develop key computer bus, board, and system specifications, such as VMEbus, PCI Mezzanine Card (PMC), VXS, VPX, and FMC, among others. Of particular interest herein is VPX, formerly known as VITA 46, which is an ANSI standard (ANSI/VITA 46.0-2007). The ANSI/VITA VPX standard defines ruggedized backplane/module card system configurations for embedded computing. Within VPX, the VITA 66 standards (hereby incorporated by reference) define the optical interfaces between the backplane and the daughter cards (e.g. VITA 66.1 connectors).
The daughter cards increasingly employ mid-board fiber optic transceivers to support data rates at or above 10 gbps. In a typical VPX system, the daughter card is populated with mid-board transceivers connected to daughter card connectors, such as VITA 66.1 connectors, using an optical fiber cable assembly. These mid-board optics modules are then connected with a fiber (typically ribbon fiber) to a VITA 66.x or other card edge connector. These cable assemblies are typically bowed/deflected/bent or contain service loops to accommodate manufacturing tolerances in the cable assemblies and to facilitate installation. Additionally, the cables are bowed to accommodate the axial displacement of the ferrule in the connector during mating. In other words, as the ferrule in the VITA 66.1 connector is pushed back during mating, the cable must be configured to bend or displace to accommodate its movement.
Applicants have identified a number of shortcomings of such a configuration. For example, if the bow in the cable assembly is excessive, the cable may interfere with the adjacent daughter cards and/or other cables on the card. Furthermore, VPX systems are typically used in aircraft and military equipment in which the environments tend to be severe (for example, high-vibration), yet reliability is critical. Vibration-induced wear, abrasion, and over bending of the cable assembles reduces their reliability. Such a configuration also does not lend itself to repair. Specifically, rework and reparability of the current state of the art is problematic as the routing of the fiber ribbons and the mid-board transceivers are integral to the daughter card assembly and are not easily replaced when failures occur in the fiber optic system.
It should be noted that the aforementioned problems are not limited to VPX-designs, but often present themselves whenever an island-mount EO module is connected to card edge connectors for blind mating.
Applicants recognized the need to eliminate the complexities of fiber cable routing for island-mount EO modules in daughter card design, not only to simplify manufacturing and increase reliability, but also to conserve valuable space on the daughter card. Applicants also recognize the need for a blindmateable EO module. Additionally, Applicants recognize that a suitable ruggedized backplane card system should comprise line replaceable units (LRUs) to facilitate repair. The present invention fulfills these needs among others.